Hedge trimming tools are required to cut vegetation ranging from small limbs, e.g. three-eighth inch diameter, down to the size of leaf stems. The conventional hedge trimming tool to which this invention is directed includes an elongated fixed blade with forwardly projected teeth and an overlying cutting blade reciprocally mounted to the fixed blade. Cutting teeth carried by the overlying cutting blade are projected over the teeth of the fixed blade and reciprocate back and forth across the spacing between the fixed blade teeth. The tool is directed into or along the hedge and as vegetation enters the space between the fixed blade teeth, it is severed by the reciprocating teeth.
Forming the teeth of the overlying cutting blade is a primary consideration in the manufacture of a hedge trimming tool. Heretofore the teeth were produced in what can essentially be considered as a two-step operation. First, holes or openings were made, e.g. by a circular punch driven through the blade thickness at the leading edge of the blade. The holes are formed so as to overlap the leading edge resulting in a scalloped configuration having hour glass configured teeth separated by C-shaped openings.
In the second step of the prior manufacturing process, a frusto conical sharpening tool, rotated on its axis, is projected down into the C-shaped openings to bevel or flare outwardly the blade thickness from the bottom surface to the top surface of the blade. This creates cutting edges along the concave curved sides of the hour glass configured teeth at the bottom surface of the blade. The blade is laid with the bottom surface flat on the fixed blade so that the cutting edges slide over the fixed blade fingers in a scissors-like slicing action.
The concern of this manner of forming the teeth is in the substantial relative cost of forming the cutting edges, i.e. the step of projecting a rotating frusto conical sharpening tool into the C-shaped openings to bevel the blade thickness and thereby form the cutting edges.